Reconstructing the ZOA from Galaxy Peculiar Velocities

Abstract

Galaxy peculiar velocity data provide important dynamical clues to the structures obscured by the Zone of Avoidance (hereafter, ZOA) with resolution >~ 500km/s. This indirect probe complements the very challenging approach of directly mapping of the distribution of galaxies behind the Milky Way. In this work, the Wiener filter method is applied to reconstruct the 3D density and velocity distributions of the universe, within ~8000km/s, using SEcat the largest peculiar velocity catalog yet. This catalog is a combination of the SFI spiral galaxy peculiar velocity catalog and the newly completed nearby early-type galaxy peculiar velocity catalog, ENEAR. The recovered density is smoothed with 900km/s Gaussian. The main reconstructed structures are consistent with those extracted from the IRAS 1.2-Jy redshift galaxy catalogs. The revealed structures are identified and their robustness and significance are discussed.